One of the great Green Arrow and Black Canary stories is 'Green Arrow: The Longbow Hunters'. It delved deep into their relationship and the grittier side of their crime - fighting in Seattle. It was a more mature take on their characters, showing their flaws and determination.
Another theme is the exploration of their individual powers and how they complement each other. The Arrow's archery skills combined with the Black Canary's sonic scream make for some exciting battle scenarios. A lot of fanfictions play around with how they can use these abilities in different situations to defeat villains.
The Green Arrow and Black Canary's romance in fanfiction is often exciting. Fanfic writers can explore their relationship in different ways. Some might focus on their initial attraction, like how their first encounters in the fictional world of the story could be filled with tension and a spark of something more. They could be in the middle of a dangerous mission and realize they have feelings for each other.
There's also 'Black Canary and Green Arrow: Partners in Peril'. This fanfiction takes them on an adventure outside of Star City. It has a great plot that includes some classic villains. The way it portrays their teamwork and the growing affection between them is really well - done.
The Green Arrow and Black Canary story is full of action and adventure. They often team up to fight crime in their city. Green Arrow is a skilled archer, and Black Canary has her martial arts skills and the Canary Cry. They face various villains together, protecting the innocent and upholding justice.
Well, a very popular theme is their partnership. Fanfictions often show how they combine their skills, with Green Arrow's archery and Black Canary's sonic scream, to take on bad guys. Family also comes up sometimes. Maybe Black Canary's family history or Green Arrow's family legacy and how it affects their relationship and actions. And of course, there are the stories that focus on their adventures in different parts of the DC world, like in Gotham or Metropolis.
I'm not entirely sure if there is a specific amount of Green Arrow and Black Canary pregnant fanfiction. It really depends on how creative the fanfiction writers in that fandom are. Some writers might be interested in exploring this aspect of their relationship, while others may focus on different storylines. You could try looking on platforms where DC Comics fanfiction is shared.